Improvement in low-water indicators



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Letters Patent No. 77,978, dated .May 19, 1868.-

IMPROVEMENT IN LOW-WATER INDICATORS.

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Be it known' that we, T.' C. Hnneanvs and W. B. CHARLTON, both of oston, in the county of Suffolk, and

State of Massachusetts, have invented e. new and improved LowvWater Indicator for Steam-Boilers; of which the following is'a full, clear, and 'exact description, reference being had to the accompanying-drawings, making e part of this specification. and representing a perspective .view of a steam-boilerand apparatus embodying our invention. i

The object of our invention is to produce a. simple and economical, and at the same time an accurate and reliable meen-s of sounding an. alarm whenever the' water shallfull below acertain level in a steam-boiler; and the inventionconsists in connecting the valve-lever of the whistle to an arm extendingfrom the indicating-tube by means of a weighted rod' in such a manner that by the expansion of the tube, caused bythe admission of steam into the same when thew-ater falls below a certa-in level, the valve will be raised and un alarm be sounded.

Referringto the drawings, .A represents a. steam-boiler, into the top of which is inserted the whistle B,

which is of'the ordinary construction..l TQ Vthe whistle-valve is attached c. lever, C, having its fulcrun in the projecting pieces b, attached to the neck-of the whistle. To the outer end of the lever is pivoted an upright rod, D, which extends through an aperture 'in an arm, F, and moves freely in the same. Thelupper end of the rod D is screw-threaded, and on the screw portion is fitted a Weight, E. The. arm F is securely fastened to the top of the indicator-tube H, and in the end of the said .tube is {itteda cock, G, Theindicator-tube is attached, at its lower end, to a pipe, I, which latter is secured in the boiler at a point below which it is desirable that the water should notfall.` -Between the indicator-tube H and pipe I is c. cock, J'. i

The operation is as follows.: When'the water in the'boiler falls to the levelof tho pipe I, that in the tubo H will'run into'the boiler. The steam will lthenenter the indicating-tube H, and by its increased heat-will Acause the said tube to expand sutliciently to raise the rod D, and open the whistle-valve, when an alarm `will be sounded.

water or steam into `the tube from the boiler, and also for cleaning the tube.

The weight E, on the rod D, serves to keep the whistle-valve securely closed withoutthe aid of'springs or The :cock G, on the -top of the ndicatortube, when open, allows` the air to escape, for the admission ofpacking, and, being fitted on the vscrewportion ofthe' rod D, admits of its ready adjustment inn-elution4 to the' arm'F forl raising the whistle-valve lever.

The whistle may be readily brought into use as :1n-ordinary alarm or signal by simply raising the-rod `D 'or lever C, 4which Work independently of the expansion or indicating-tube.

VBy placing the fulcrunl of'the whistle-valve lever nt the end, instead o'f at the centre, und reversing the valve, the whistle 'can be m'ade tio-sound when the amount `of pressure is reached Whichit is desredto carry,.

and thus furnish a safety-pressurennd alarm-valve,.as well asa'low-watci indicator. I -We' make no ola'imlto an expenebletube, as we are aware that such has long been in use, but

Whatl we claim, and desire-to secure by Letters Patent, is-- 1 The-arrangement'of lthe pipeL'expansion-tube H, provided with the cock G, arm F, adjustable weighted` rod D, in connection with thelever C and whistle B,'"substantiullyas. and for the purpose set forth.

In testimony whereor, 'we' .have eig-ned o ur. names toi'this specification in the presence of two subscribing wituesses.-

T. C. HARGRAVE,J

W. B. CHARLTON.

Witnesses:

Jos, H. Anims, M. G. WILBE. 

